The following guest article is intended to stimulate discussion among FACT Net participants. The opinions expressed by the author are not necessarily those of FACT Net. We welcome your opinions on this topic in written form. Mark Powell, FACT Net Coordinator.
Increasing emphasis has been placed over the last 25 years on agroforestry and other products from trees and woody perennials such as fuel, fodder, food, raw materials and medicines. Much research has been undertaken on identifying suitable species, systems and developing these products for the benefit of poor farmers, hoping to sustain production and rural livelihoods. Fuel and fodder are low value products, and although essential to sustaining life, can rarely improve it. Under-exploited fruits and raw materials for industry (e.g. pharmaceutical compounds) have the potential for high value production from agroforests, but while forever looking at these other products, we seem to have forgotten the basic product of trees—wood for timber.
World demand for timber is steadily increasing. Low value softwoods and wood for pulp are presently produced on industrial scale plantations, and will probably continue to be so. At the other end of the wood value scale, there are high quality hardwoods, with the bulk of world supplies from moist tropical and sub-tropical forests. These cannot be expected to meet the increasing demand, especially with increasing pressure on land for agriculture and the need to preserve remaining natural forests for the ‘global good’. There is a great need to investigate the production of commercial timber on land presently producing agricultural and livestock products.
Many trees already cultivated for other products also produce quality timber that is very much under-exploited. Such timber is ideally produced on wide spacing and as such this lends itself to agroforestry systems. Pruning for clear bole and increased timber value will also reduce competition with neighboring crops and grasses for light and water. There is a strong need to evaluate many other trees for timber quality, and the economics of production
within such land use systems. Large bole size is now not a pre-requisite for a commercial timber tree, with a market in small timber ‘blanks’ for the furniture industry and existing processing technologies available. Opportunity costs for land may make this viable on marginal agricultural land, but species need selecting and commodity chain analyses are required. ‘Savanna’ ecosystems appear particularly well suited to such systems.
Foresters have been given bad press in development circles for some years for promoting land use that was monocultural and did not include the community, in fact positively excluded it. Public pressure in the West—linking timber production with logging of tropical rain forests—influenced donor agencies to allocate more funds for social and community forestry, often with the aim of producing non-timber forest products (NTFPs). With the demise of traditional forestry, from where can we be expected to supply the growing needs for timber and timber products from developing and developed countries alike? In many developing countries foresters manage dwindling forest reserves and ‘agroforests’. In India for example, NTFPs now account for 70-80% of the revenue earned from forests. Urgent changes are required to promote timber production as a sustainable output from agroforestry systems.
We have swung too far in our attempts to ‘harmonize’ tree production with the needs of farmers and farming communities. There is a need to impress again that it is acceptable to cut down trees and sell timber for cash income. The industry of felling, processing and selling, gives value to trees. This creates investment opportunities, which are required for tree planting in the future, both on farm and in forests. Planting private forests as an investment for timber, and reducing the cost of forest establishment through the production of NTFPs, is a viable option for increasing rural livelihoods and encouraging private long-term investment in the land.
Henry Doubleday Research Association
Coventry, United Kingdom.
Fax: + 44 (0) 1203 639229
Forest, Farm and Community Tree Research Reports, Vlume 3, 1998 and Domestication fo Agroforestry Trees in Southeast asia, FACTRR Special Issue 1999 were mailed to “professional” level participants in March. Additional copies may be purchased from FACT Net.
Tephrosia vogelii is a small nitrogen-fixing shrub (to 4 m in height) native to tropical Africa. It grows in a range of sites including savannas, forest margins and fallow fields. It is used in Southern Africa to improve soil, as fuelwood, and as an insecticide against storage pests and mites on plants.
Tephrosia leaves and seeds contain Tephrosine, which makes the tree unpalatable to goats and other browsing animals. Tephrosine also makes the tree resistant to termites.
In alley cropping with maize, tephrosia is direct seeded at a spacing of 90 cm with 2–3 seeds per planting hole. Rows of tephrosia are alternated with maize rows. Seeds germinate 8–10 days after sowing and seedlings grow slowly—careful and frequent weeding is necessary during the early stages of growth.
After the maize has been harvested, the tephrosia shrubs are left to grow until the land is prepared for the next growing season. Before planting the next crop, tephrosia shrubs are cut at ground level. Main stems may be used for firewood or may be chopped up for incorporation into the soil with smaller branches, twigs, and leaves.
Tephosia is attacked by the same nematodes that attacks tobacco, tomato, eggplant, paprika and green peppers. It should not be planted on sites where any of these, or related plants, have been grown, or will be grown.
Dr. Andreas Boehringer
ICRAF Zambezi Basin Agroforestry Project
for Sustainable Rural Development
P.O. Box 134
Phone: 265 534 289; Fax: 265 534 29
There are nineteen interesting articles in the latest volume of FACTRR. Here are summaries of two of them.
Cutting interval and tree age at first cutting affect herbage production of six hedgerow tree species. Blesilda M. Calub. This three-year experiment in the Philippines evaluated leaf and wood biomass production of Bauhinia monandra, Erythrina orientalis (syn. variegata), Gliricidia sepium, Leucaena leucocephala, Moringa oleifera and Pithecelobium dulce at first cutting (6, 9 and 12 weeks) and three cutting intervals (8, 12 and 16 weeks). Cutting height was 1 m for all species.
This study found no significant interaction effects between cutting interval and tree age at first cutting, but cutting interval as a single factor significantly influenced dry-matter yield. Over three years, G. sepium, B. monandra, and L. leucocephala produced the highest average dry-matter yields with a high proportion of leafy biomass when cut at an 8-week interval. Lowest total dry-matter yields of low leaf proportion were obtained from M. oleifera. No significant differences in dry-matter yields were observed in E. orientalis and P. dulce. Employing a 16-week cutting interval resulted in the highest total dry-matter yields in G. sepium and B monandra, but the proportion of leafy biomass was significantly reduced.
Appropriateness of Vitex pubescens production for swidden agriculturists. Wil de Jong, R. Utama, D. Rantan, S. Budhi, S. Kusmina and F. Sriwardani. Vitex pubescens is a pioneer tree species that invades grasslands dominated by Imperata cylindrica in West Kalimantan, Indonesia. A study was conducted to determine its potential for income generation for smallholder farmers. Early results indicate that charcoal production may be a profitable enterprise. A well-established stand of this species with a density of 2500 trees/ha can yield, per tree, about 10 branch cuttings of 1 m length with an average diameter of 8–12 cm every three to four years, or 25,000 branch cuttings/ha. One hundred and twenty branch cuttings yield one stacked m3, hence one hectare of V. pubescens may yield over 200 m3. This amount can be converted into 16–18 tons of charcoal with a value of about US$ 1,000.
The planting and harvesting of V. pubescens and the production of charcoal can be scheduled around other agricultural activities, during rainy days for instance, when rubber cannot be tapped, or in a period when rice fields do not need attention.